The present invention relates generally to a tuning apparatus and, more particularly, is directed to a tuning apparatus having automatic and manual tuning operations.
One type of a presettable tuning apparatus known in the art is shown in the U.S. Pat. No. 4,167,702, entitled "TUNING APPARATUS". In this tuning apparatus, markers corresponding to a desired number of broadcast stations can be preset in relation to a dial plate having broadcast frequencies marked thereon. However, each time that it is desired to receive a preset station, the tuning knob in this apparatus must be rotated to position the pointer mount assembly into alignment with a previously preset marker. That is, there is no automatic reception of a preset station. Also, this apparatus uses a mechanical variable capacitor to control the frequency of a local oscillator, resulting in a complicated and expensive construction of the tuning apparatus. Although an electronic tuner, in which a voltage-variable capacitance element is used at the front end portion of the tuner, is generally known, this type of tuner does not include a dial plate and markers which can preset a desired broadcast station.
Also known in the art are presettable radio receivers for selecting two or more broadcasting stations beforehand, in which a desired broadcasting station can be selected from among the preselected broadcasting stations by depressing a push-button or the like. However, such presettable radio receivers employ a number of .mu.-tuning elements corresponding to the number of desired broadcasting stations to be selected. Accordingly, these devices are of a complex construction, are difficult to adjust, and typically involve high manufacturing costs.